Project Summary/Abstract Mental illness costs the United States 1.93 billion in lost earnings per year and suicide, which often occurs in the context of mental health problems, is the 10th highest cause of death leading to an estimated 40,000 deaths annually. Lesbian, gay, and bisexual (LGB) adults are twice as likely as heterosexual adults to have been diagnosed with a mental health disorder. Additionally, 60% of LGB adolescents compared to 26% of heterosexual adolescents report feeling sad and hopeless for most days in a two-week period. Thus, LGB youth and adults are disproportionally affected by these economic and mortality issues. Mental health disparities within the LGB population differ by race, gender, and sexual identity. Understanding health disparities among sexual minorities is a critical health imperative and focus the National Institutes of Health. The link between gender, race, sexual identity discrimination, underlying causes of health disparities, and mental health is an urgent concern for researchers and health care professionals. Few studies explore how gender, race and sexual identity discriminatory experiences are independently and concurrently associated with mental health trajectories in the LGB population. This Predoctoral Fellowship to Promote Diversity in Health-Related Research (F31-Diversity) would allow the applicant to address this gap through his research and training plan. The main objective of Mr. Mallory?s project is to understand how race, gender, and sexual identity discrimination independently and in different combinations are associated with mental health trajectories. He will accomplish this objective with two aims: (Aim 1) elucidating the individual longitudinal associations between race, gender, and sexual identity discrimination and mental health trajectories for LGB youth and adults and (Aim 2) testing three competing explanations of how multiple forms of discrimination jointly to impact trajectories of mental health for LGB youth and adults. The competing explanations are that discrimination is (1) additive: for each additional form of discrimination, mental health will incrementally worsen; (2) exacerbating: mental health symptoms are two and three times worse when experiencing two and three forms of discrimination; and (3) inuring: mental health does not worsen beyond one form of discrimination. To accomplish the objective and aims of his proposed research plan Mr. Mallory will seek out additional training in analyzing large longitudinal data sets with complex data structures, learning population health and life course theoretical perspectives, and applying an intersectional framework to his research which will augment his core training in Human Development and Family Sciences. His training plan combines formal coursework in population health and statistics, workshops that integrate method, theory, and analysis for analyzing quantitative data from an intersectional framework, one-on-one mentoring, conference presentations, and publishing research to prepare him for a career as an independent researcher.